Contents
- Introduction
- 1. Theme urgency
- 2. Goal and objectives of the study
- 3. Description mill
- 4. Preparing metal for rolling
- References
Introduction
To broadband mill hot rolling (WS HRM) include mnogoletie mills with the placement of stands in the roughing and finishing groups. In the roughing group is used as irreversible and reversible crate located discontinuously or continuously, and in the finishing group of stand always located continuously. All the products in wide-strip rolling mills is wound in rolls on reels. Wide-strip rolling mills for sheet and strip rolled products with thickness from 0.8 to 27 mm and widths of up to 2350 m. the Main assortment of mills of this type – strip thickness of 1.2 to 16 mm. In the 70-ies of the last century posed the problem of rolling of strips with thickness of 0,8–1 mm on wide-strip rolling mills, and the assortment of mills 1780 company "Sumitomo to Kinzoku Kogyo in Kashima (Japan) and 2285 of the company "Colmar" (France) in FOS-sur-Mer was provided and was used for the rolling of strips of such thickness. Practice has shown that rolling of strips with thickness less than 1.2 mm dramatically reduces the performance of wide-strip rolling mills, creates the difficulty in transporting the front end of the strips to the winders, and most importantly – the quality of these bands almost all indicators worse than cold-rolled. Technical progress in technology, equipment, and most importantly – in the automation of WS HRM again in the late 80-ies of the last century provoked a re-formulation of the problem of rolling of strips with thickness of 0,8–1 mm. Grade mix WS HRM – ordinary and quality carbon, low alloy, stainless and electrical steel grades. Assortment of wide-strip rolling mills, as well as some basic parameters are given in tab.1.1 (CIS) and in table.1.2 (foreign countries). The development of broadband hot rolling mills is to increase the mass of the slabs, increase the speed of rolling, a wider assortment of strips, productivity growth and increase of requirements to quality of finished products, the scope of which is expanding all the time..
1. Theme urgency
Optimization of the distribution of reductions in vertical rolls, to ensure the quality of the edges, a predetermined width and minimum vibrations along the length, hence,improving the quality of rolled products.
2.Goal and objectives of the study
Goal - to master the methodology of rational distribution of reductions in vertical rollers
3. Description mill
Continuous broadband mill 2000 Novolipetsk metallurgical combine The mill was commissioned in 1969, the plant's Equipment is located in two independent buildings. One is the main equipment of the mill with heating furnaces, mill stands, coilers, in the other - finishing equipment with the units cutting rolls of trademark leaves and their finishing. Mill 2000 is intended for rolling of strips with thickness 1,2 -16,0 mm, width mm. On the 1000-1850 mill rolled steel:carbon ordinary quality, quality carbon structural, low alloy plate, carbon and low alloy for shipbuilding , carbon and low alloy for the manufacture of gas-and-oil pipes and pipes of General purpose, quality carbon and low-carbon high-quality for cold rolling.
4. Preparing metal for rolling
A billet for rolling continuous cast slabs is in the Converter shops ¹1 and ¹ 2. The slabs are sent to the warehouse,where they inspected and cleaned. Then the slabs are served on the lifting tables of the loading device and transportyou to reheating furnaces. The area consists of 15 sections, loading roller table, three lifting tables with stalkivalas slabs and scales for weighing them. For heating slabs in the shop is equipped with 5 furnaces. Type of furnace – methodological multi-zone, two-lane, two-way heating the metal, with end Posad and results of slabs. Furnace No. 1-No. 3 – pusher with picsanime pipes. The system of automatic regulation of thermal mode of heating furnaces ensures uniform heating of the slabs to a predetermined temperature. The system incorporates the following independent controls: in the zones of the furnace; the ratio of gas-air between the zones of the furnace; gas ratio-gas to the furnaces, support given calorie mixture of natural and blast furnace gases; pressure regulators in the furnace; the temperature of the air which protect the fans, the regulators level is adequate water in the drum separator of an evaporative cooling system. Each oven is equipped with an automatic optimum heating and automatic gas cut-off. To load the slabs into the furnace installed lifting tables with stalkivalas. Lifting tables are designed to receive the stop slab height <1000 mm, weight <120 t lifting those feet, the thickness of the slab to push it to the startup grid.
Vertical swath (VV) of the universal roughing stands of continuous broadband mill (ENM) are used to remove the broadening of the metal during rolling in the rolls of the horizontal (HS) and compression of the lateral edges of rolls to avoid their tears. Added to this is the fact that reduced ranges of fluctuation width along the length of the peals and peals of parties compared to the reference slabs, and the deviation of form of rolls in the plan from rectangular, as a result of compensation of contraction con-EAI Bang and the formation of the concavity the ends after compression in the subsequent CENTURIES thereafter formation of fan-shaped widening of the ends and the convexity of the rusk-that after compression in the horizontal rollers (GW). Based on these while in immigration prison of the tions of the absolute value of reductions in universal BB stands WS HRM needs to be in the range of 25-35 mm. In this regard, the rational allocation of reductions in the BB is an urgent task. Design of vertical roller node stands are similar to the horizontal node. To enable vertical movement of the crate on the rack, with one side frame is equipped with guides with a T-groove. In the bottom of the frame has four rollers 4, on which the crate rolls on the horizontal guides of the column when handling.
References
1. Lopuhin V. A. Modern continuous broadband mill hot and cold rolling of Japan // Bulletin of the Institute of "chermetinformatsiya".-1972.-No. 2.- Pp. 3-14.
2. Oratovski E. L., Lopuhin V. A., Artamonova E. A., Continuous and semi-continuous broadband hot rolling mills // the Bulletin of the Institute chermetinformatsiya".- 1980.- ¹13.- S. 22-35.
3. Zyuzin V. I., Browman M. Y., Melnikov, A. F., deformation Resistance of steels during hot rolling. – M.: Metallurgy, 1964. – 270.
4. Swarov D. I., F. S. Gilevich Calculation of optimal modes during hot rolling wide strip reversing mills. – Krasnoyarsk book publishing house, 1971. –111ñ
5. Browman, M. J., Zaplaceno B. Yu., Gertsev, A. I., improving the technology of rolling of thick leaves. – M.: Metallurgy, 1969. – 253ñ.